#!/bin/bash
#read -p "input a string: " a
if [ $# -eq 0 ] || [ $# -gt 1 ]
then
    echo "usage:/home/hello.sh hello or world"
    #echo "usage:`basename $0` world or hello"
elif [ "$1" = "hello" ]
then
    echo "world"
elif [ "$1" = "world" ]
then
    echo "hello"
else
    echo "usage:/home/hello.sh hello or world"
fi
